Robotic Guitarist (free) is a guitar emulator with a chord guide and a metronome, for those of us that need to play around a bit with hearing and seeing the chords before it starts to make sense in our brain, and by extension, our fingers.

Guitarist's Reference

Guitarist's Reference ($2.99) is recommended for those wishing to brush up on their music theory, with a massive index of chords, scales, scale relationships, alternate tunings and arpeggio diagrams.

Have you used tech to learn an instrument? Do you have a favorite guitar app for Android? Share it with us in the comments below.